1. Technical field
The present invention relates to an elevator door with an improved clutch device, and more particularly to a clutch system of an elevator door suitable for increasing clutch speed and decreasing clutch distance of a car door and a hatch door.
2. Description of the Prior Art
As the buildings are higher, there is need to provide an elevator, which may carry passengers to a destined floor faster. Faster movement of the elevator requires increasing vertical speed of the elevator as well as shortening time to open or close an elevator door.
Among those, the present invention deals with a technique of reducing time to open or close elevator doors with ensuring stable operation of the elevator doors.
The elevator door generally includes a car door installed to an elevator car and a hatch door installed to entrance of the elevator car in each floor. The car door may open with use of a driving unit mounted on the elevator car, while the hatch door moves along with the car door with use of a clutch system. In order to move the hatch door along with the car door, the clutch system performs a series of clutch operation, which will be explained in detail below.
Opening speed of the car door until completing the clutch operation of the car door and the hatch door (hereinafter, referred to "clutch speed") is important to door opening time. As the clutch speed is slower, time to open or close the elevator door increases, which makes it inefficient to carry passengers fast. Therefore, increase of the clutch speed of the car door and the hatch door helps to reduce the time to open or close the doors.
FIG. 1 and FIG. 2 are horizontal section view and vertical section view respectively showing schematic configuration of a conventional elevator. As shown in the figures, the elevator car 2 carries passengers with moving vertically in hoist way 1 by a separate driving unit. The car door 10 is installed at entrance of the elevator car 2 to open and close laterally. The hatch door 20 is positioned at each floor of a building, which the elevator serves, in order to allow passengers to enter the elevator car 2. The elevator door is a common name for designating both the car door 10 and the hatch door 20.
Unexplained reference 3 is for a counter weight.
FIG. 3 is a front view showing the elevator door according to the prior art, viewed at a car door side. Referring to the figure, a door motor 4 is mounted on the elevator car 2 for providing power to open or close the car door 10. At one side of the door motor 4, first and second reduction pulleys 5a, 5b are sequentially installed to reduce rotating speed of the door motor 4. The second reducing pulley 5b is combined with one end of a moving link 6 such that the moving link 6 may move in linkage with rotation of the second reduction pulley 5b. The other end of the moving link 6 is rotatably combined with one end of a main link 7, which is also rotatably combined with the elevator car 2. The other end of the main link 7 is rotatably combined with a cam link 13, which is positioned at a left door panel 10a. Viewed from the figure, a pair of clutch plates 11, 12 are installed at the left door panel 10a, a fixed clutch plate 11 of which the cam link 13 is rotatably combined with. A car frame 31 is mounted upon the elevator car 2 for supporting the elevator car 2. The main link 7 is fixed to the car frame 31 with a rotating joint 7a at its mediate portion to possibly rotate on center of the rotating joint 7a. A connecting link 8 is combined with an upper mediate portion of the main link 7. The other end of the connecting link 8 is rotatably connected to a certain position of a sub-link 9 at a right door panel 10b. One end of the sub-link 9 is rotatably fixed to the car frame 31 with a rotating joint 9a, while the other end is also rotatably combined with one end of a cam link 16. Viewed from the figure, a pair of clutch plates 14, 15 is installed to the right door panel 10b, a fixed clutch plate 14 of which the cam link 16 is rotatably combined with.
A pair of clutch plates 11, 12 or 14, 15 at the left or right door panel 10a or 10b includes the fixed clutch plate 11 or 14 and a movable clutch plate 12 or 15. The fixed clutch plate 11 or 14 is fixed to each door panel 10a, 10b, and the cam link 13 or 16 is rotatably combined with the fixed clutch plate 11, 14 as described above. The movable clutch plate 12, 15 is combined with the fixed clutch plate 11, 14 with a hinge 17a or 17b, which is well shown in FIG. 5 and FIG. 7.
Referring to FIG. 4 and FIG. 5, a pair of clutch rollers 21, 22 or 23, 24 is installed to each door panel 20a, 20b of the hatch door 20. The clutch rollers 21, 22 or 23, 24 include a fixed clutch roller 21 or 23 and a rotating clutch roller 22 or 24. The pair of clutch plates 11, 12 or 14, 15 are installed to have certain clearance therebetween, such that the clutch rollers 21, 22 or 23, 24 may pass through the clearance when the elevator car is moving. However, when the elevator car 2 arrives at a destined floor, the clutch rollers 21, 22 or 23, 24 are interposed between and becomes contacted with the pair of clutch plates 11, 12 or 14, 15 for the purpose of opening or closing the hatch door 20 along with the car door 10.
FIG. 6 and FIG. 7 are front and horizontal section views respectively showing the clutch system of the conventional elevator door. Referring to the figures, one end of the cam link 13 or 16 is rotatably combined with the main or sub-link 7 or 9 with a rotating joint J, while a roller 13a or 16a is mounted to the other end to freely rotate. A rugged cam 12a or 15a is formed on a side of the movable clutch plate 12 or 15 such that the roller 13a, 16a of the cam link 13, 16 may roll in contact with the rugged cam 12a, 15a. On the rugged cam 12a, 15a, a plurality of curved portions are formed in succession such that angular displacement of the movable clutch plate 12, 15 may be determined according to the height of the curved portions.
The fixed clutch plate 11, 14 and the movable clutch plate 12, 15 of the car door 10 and the fixed clutch roller 21, 23 and the rotating clutch roller 22, 24 of the hatch door 20 are installed to the left and right door panels 10a, 10b and 20a, 20b in mirror image.
The elevator door with the conventional clutch device as constructed above operates as follows.
At first when the elevator car 2 arrives at a destined floor, a door opening command is generated. The door motor 4 then starts to rotate clockwise according to the door opening command. Rotation of the door motor 4 is reduced through the first and second reduction pulley 5a, 5b and then moves the moving link 6. If the moving link 6 moves in linkage with the second reduction pulley 5b, one end of the main link 7 connected to the moving link 6 angularly moves clockwise. At this time, because the main link 7 is constructed to rotate on center of the rotating joint 7a at the mediate portion thereof, the other end of the main link 7 also rotates clockwise. When the other end of the main link 7 rotates clockwise, the cam link 13 of the left door panel 10a angularly moves counterclockwise, which makes the left door panel 10a opened left. On the other hand, clockwise rotation of the main link 7 is linked with the connecting link 8, one end of which is combined at an upper mediate portion of the main link 7, and then linked with the sub-link 9 combined with the other end of the connecting link 8. However, while the main link 7 rotates clockwise, the sub-link 9, one end of which is rotatably fixed to the car frame 31 with the rotating joint 9a, rotates counterclockwise. If the sub-link 9 rotates counterclockwise, the cam link 16 of the right door panel 10b angularly moves counterclockwise, which makes the right door panel 10b opened aright.
At this point, when each cam link 13, 16 angularly moves clockwise or counterclockwise, the roller 13a, 16a of each cam link 13, 16 moves along the curved portion of the rugged cam 12a, 15a. Due to variation of the depth of the curved portion, the movable clutch plates 12, 15 of the left and right door panels 10a, 10b angularly moves on center of the hinges 17a, 17b on the fixed clutch plates 11, 14. Due to rotation of the movable clutch plate 12, 15, the fixed and rotating clutch rollers 21, 23 and 22, 24 are closely contacted between the fixed and movable clutch plates 11, 14 and 12, 15, which is completion of the clutch operation.
After that, the left and right hatch door panel 20a, 20b are opened to opposite directions according to movement of the left and right car door panel 10a, 10b, which makes the elevator door open.
Such serial clutch operation is explained in detail with reference to FIG. 8 to FIG. 11. FIG. 8 to FIG. 11 show the clutch operation of the clutch device according to the conventional elevator door in sequence, all of which have vertical section view and side view.
At first, FIG. 8 shows clutch operation of the car door 10 and the hatch door 20 at the time that the elevator car 2 is moving or arrives at a destined floor. Referring to the figure, the clutch plates 11, 12 and 14, 15 of the car door 10 and the clutch rollers 21, 22 and 23, 24 of the hatch door 20 maintain clearance therebetween as much as G1 at this time. After that, when the car door 10 starts opening, the car door 10 moves while the hatch door 20 maintains its closed position until the fixed clutch plate 11, 14 of the car door 10 comes in contact with the rotating clutch roller 22, 24 of the hatch door 20.
Next, FIG. 9 shows the time that the clutch operation begins between the car door 10 and the hatch door 20. Referring to figure, moving distance of the car door 10 until the fixed clutch plate 11, 14 of the car door 10 comes in contact with the rotating clutch roller 22, 24 of the hatch door 20 corresponds to Sl. As the car door 10 opens as much as S1, angular displacement of the cam link 13, 16 is from A1 to A2. In addition, the angular displacement of the cam link 13, 16 causes the movable clutch plate 12, 15 to angularly move on center of the hinge 17a, 17b. At this time, the left and right hatch door panels 20a, 20b moves along with the left and right car door panels 10a, 10b and clearance between the movable clutch plate 12, 15 of the car door 10 and the fixed clutch roller 21, 23 of the hatch door 10 becomes G2. Furthermore, clutching state, at this time, is not perfect because of the clearance G2 between the movable clutch plate 12, 15 of the car door 10 and the fixed clutch roller 21, 23 of the hatch door 20, while the fixed clutch plate 11, 14 of the car door 10 is in contact with the rotating clutch roller 22, 24 of the hatch door 20.
Next, FIG. 10 shows the time that the hatch door 20 starts to move along with the car door 10. At this time, the car door 10 advances a little more than that of FIG. 9. Referring to the figure, angle of the cam link 13, 16 displaces from A2 to A3. In addition, the movable clutch plate 12, 15 begins to rotate on center of the hinge 17a, 17b due to the angular displacement of the cam link 13, 16. Clearance between the movable clutch plate 12, 15 of the car door 10 and the fixed clutch roller 21, 23 of the hatch door 20 becomes G3 due to angular movement of the movable clutch plate 12, 15, which is slightly narrower than G2 at the time that the car door 10 moves as much as S1. In FIG. 10, the car door 10 moves as much as S2, which is more advanced than S1.
Finally, FIG. 11 shows the time that the clutch operation between the car door 10 and the hatch door 20 is completed. As shown in the figure, if the car door 10 continues to move until as much as S3, the movable clutch plate 12, 15 of the car door 10 comes in contact with the fixed clutch roller 21, 23 of the hatch door 20 so to make clearance therebetween changed into 0 from S3. This is completion of the clutch operation between the car door 10 and the hatch door 20. From closed state to the completion of the clutch operation, the car door 10 moves as much as S3, which is called as "clutch completion distance".
When opening the door, the car door 10 and the hatch door 20 moves at a low speed until completion of the clutch operation, and at a high speed after the completion of the clutch operation.
Closing process of the elevator door is the reverse of the door opening process.
For the purpose of reducing time to open the conventional elevator door, there are methods of both or either increasing the clutch speed and/or reducing the clutch completion distance S3. However, in case of increasing the clutch speed, noises and vibration may be generated due to impact when the movable clutch plate 12, 15 of the car door 10 contacts with the fixed clutch roller 21, 23 of the hatch door 20. On the other hand, in case of reducing the clutch completion distance, the curved portion of the rugged cam 12a, 15a should having a steep inflection point in the light of angular displacement of the cam link 13, 16 required to contact the movable clutch plate 12, 15 of the car door 10 to the fixed clutch roller 21, 23 of the hatch door 20. However, such configuration requires stronger force for the roller 13a, 16a of the cam link 13, 16 to move along the steep slope of the rugged cam 12a, 15a, which may cause a problem of the door motor 4 to be overloaded.